The present invention disclosed herein relates to an electric motor, and more particularly, to a Brushless Direct Current (BLDC) motor system and a driving method of a BLDC motor.
BLDC motors are configured with a stator using an armature, and a rotor using a permanent magnet. BLDC motors commutate a current that flows in coils of an armature, for forming a continuous rotating magnetic field that rotates a rotator. In BLDC motors, the continuous rotating magnetic field for rotating the rotator is formed when the position of the rotator is matched with a commutation time.
As a method of detecting the position of a rotator, a hall sensor is used. The hall sensor senses an electric field to detect the position of a permanent magnet in the rotator. However, the hall sensor is vulnerable to a high-temperature and high-pressure environment, and when the hall sensor is not inserted into an accurate position, the hall sensor outputs a wrong output value.
As another method of detecting the position of a rotator, a sensorless BLDC motor driving circuit is used. The sensorless BLDC motor driving circuit detects a counter electro-motive force that is formed in coils of a BLDC motor, thereby detecting the position of a permanent magnet in the rotator.